Graphene battery as energy storage for appliances

ABSTRACT

A supercapacitor having multiple graphene layers that are separated by separator layers. The graphene layers and the separator layers are enclosed within a housing that is filled with electrolyte

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 63/238,978, filed Aug. 31, 2021, which is incorporated herein by reference in its entirety.

BACKGROUND

The average home in California uses around half as much energy as the average American household. However, California households pay the highest rates in the entire country. In fact, Californians pay around $1,700 per household/per year for electricity, and rates continue to rise. This is due to the state's many renewable-energy mandates and transmission-system upgrades.

Although other factors can increase electricity usage, air conditioning represents a large expense for most homeowners. This is especially true for those living in warmer areas where electricity rates are high. During peak months and times, air conditioning alone can cost homeowners hundreds of dollars each month. It's not just homeowners that suffer with higher costs during summer. Businesses spend a considerable amount of money on energy bills during the hottest times of the year. For example, Americans spend more than $22 billion a year on electricity to cool their homes with air conditioning.

According to the US Department of Energy, consumers use approximately 183 billion kilowatt-hours to cool their homes. This accounts for 15% of all energy used in most homes and can represent up to 70% of a summer electricity bill for residents living in warmer climates.

Power outages also present a serious problem for businesses of all shapes and sizes. Businesses, regardless of their size, require power every day to run their operations. When the power goes out, downtime occurs, costing businesses thousands, if not millions, of dollars. Long-lasting outages can cause irreversible damage. It's crucial that leaders create a plan to prevent power outages from negatively impacting their business.

For consumers, power outages represent a major problem. When an natural disaster such as an Artic blast overwhelms a power grid, thousands of residents that relies on power for their ventilators, heating systems, and other medically-necessary devices may find themselves fighting to stay comfortable and alive as temperatures dropped dangerously low. During this time, even gas generators couldn't keep up. Residents around the state waited days for their power to return.

It's predicted that these weather events will happen more frequently in the coming years. This, combined with an aging power grid, means real trouble for homeowners and businesses around the country. It's never been more important to have a back-up plan for power. Mint Controls brings that option to the table.

Despite growing storage demands, many warehouses around the U.S. sit relatively empty. In fact, most warehouses only use around 20% of their available space. As American businesses compete to bring new products to market faster, and at a much higher volume, the need for available storage space skyrockets, putting warehouses and third-party logistics (3PL) companies in a position of power. Unfortunately, without a way to advertise their storage capabilities, these warehouses often do not attract repeat customers, leaving the potential for significant revenues untapped.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates an exploded view of a supercapacitor according to an embodiment of the present disclosure;

FIG. 2 illustrates an exploded view of another supercapacitor according to an embodiment of the present disclosure;

FIG. 3 illustrates a cross-section of a supercapacitor according to an embodiment of the present disclosure;

FIGS. 4A and 4B illustrate various supercapacitor configurations according to an embodiment of the present disclosure; and

FIG. 5 illustrates a coating for an electrode plate in a supercapacitor according to an embodiment of the present disclosure.

Embodiments of the present disclosure and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures, wherein showings therein are for purposes of illustrating embodiments of the present disclosure and not for purposes of limiting the same.

DETAILED DESCRIPTION

As energy needs increase, consumers and businesses look for ways to reduce their energy costs and improve reliability. While alternative options exist, these options depend on factors outside the general public's control. In order to make power sources like wind and solar a viable option for consumers, the energy must be collected and properly stored with minimal loss of energy.

Graphene batteries provide a superior energy solution for businesses and residential environments. Graphene provides a flexible and customizable option. The battery can be custom-tailored for a variety of situations. For example, graphene batteries can be installed directly on an air conditioning unit or other major appliance. The graphene battery charges at night or through solar power, and provides adequate electricity to the unit. This solution reduces or eliminates electricity costs and creates a powerwall for the home or business.

A powerwall is an integrated battery back-up. It provides power to the home or business in the event of a power outage. The system collects and stores energy from solar or other sources for access when and where it is needed most.

An increasing number of consumers have already started installing backup power supplies in their homes and businesses. These systems are either grid-tied or fully independent. They draw power directly from the grid or from solar panels installed on the home or business.

The solution disclosed herein takes the power wall system one step further by using graphene. Unlike other capacitors that use lithium-ion or a lithium nickel manganese cobalt oxide (NMC) battery, graphene can hold up to 1,000 Wh per kilogram while Lithium-ion can only store up to 180 Wh per kilogram. Graphene is also safer than other options. Lithium-ion is prone to overheating, overcharging, and puncture—all of which can cause disastrous results for the home or business where installed. graphene is more stable, flexible, stronger, and more resilient to potential issues.

Energy Storage

Energy storage allows homeowners and businesses to save money while ensuring continuous power, even during rolling blackouts and outages. Energy storage reduces the cost to provide frequency regulation and spinning reserve services. Energy storage offsets the cost to consumers by allowing them to store low-cost energy for use during peak periods when electricity rates are high.

During power outages, the right energy storage solution allows businesses to avoid costly disruptions and continue business as normal. Homeowners and renters can prevent spoiled food and medicines and keep important appliances and devices running, even during extended outages. This helps consumers prevent temperature-related illness while avoiding the inconvenience of rolling blackouts and outages caused by other factors.

The same concept that applies to backup power for personal devices can be scaled to provide power to an entire building or even the entire grid.

Energy storage smooths out the delivery of variable or intermittent resources by storing excess energy at peak times and delivering it when conditions are not favorable for energy collection. Energy storage supports the efficient delivery of electricity for inflexible baseload resources. When demand changes rapidly and increased flexibility is required, energy storage can be used to inject or extract electricity as needed to match load. For example, a computer system that connects an energy storage device that includes graphene battery of a premises and the electricity grid may monitor load corresponding to the electricity grid. When an anomaly is detected (e.g., a power outage, energy demand exceeds a threshold for the electricity grid), the computer system may trigger a switch to provide electricity to appliances of the house using energy from the energy storage device. In some embodiments, the computer system may completely switch the power source over to the energy storage device such that the energy storage device becomes the sole power source for the appliances of the premises. In some embodiments, the computer system may use the power from the energy storage device to supplement the power from the electricity grid. The transition may be seamless such that it does not cause any interruptions to the usage of the appliances for the user.

Energy storage allows electricity to be stored for when and where it is needed most. The right energy storage solution reduces greenhouse gas emissions and introduces more efficiency and flexibility to the grid. As cleaner energy gets introduced to the existing energy supply, American reliance on pollution-emitting peak power plants and other threats to the environment decreases.

By using the solution disclosed herein, consumers and businesses can ensure proper and safe storage of energy. The specially-designed graphene battery charges and dumps in very little time, allowing for multiple cycles throughout the day.

The graphene battery provides safe and reliable power for up to one million cycles and at least fifty years. Adding solar increases battery potential, protecting against power outages for even longer periods of time. The energy storage solution disclosed herein can be used in multiple scenarios and situations. Homeowners and businesses can use the solution to reduce energy costs and ensure continuous power. When used to power home appliances, the Graphene Solution ensures cost-efficient cooling while effectively creating a powerwall protection for the home.

Graphene

Graphene is a single layer of carbon atoms, tightly bound in a hexagonal honeycomb lattice. At just 1 atom thick, graphene can be made 100-300 times stronger than steel. In addition to this compound's excellent strength, it is also the best conductor of heat at room temperature and, most importantly, electricity.

Graphene's electron mobility in one hundred times faster than silicon. Graphene conducts heat two times better than diamond. Its electrical conductivity is thirteen times better than copper. Because graphene absorbs only 2.3% of reflected light, it is impervious. Even helium (the smallest atom) cannot pass through a monolayer graphene sheet.

Graphene is currently the most studied material on Earth. Mint Controls has performed extensive testing and research on the Company's Graphene Battery and Graphene Solutions. Testing has revealed the viability of the Graphene Solution as a safe and effective energy storage solution for homes and businesses.

Characteristics of Graphene

High capacitance density (C/V ca. 90,000 F/l to ca. 300,000 F/l or higher)

Capacitance per mass (C/M ca. 40,000 F/Kg to ca. 150,000 F/Kg or higher)

Energy density (S/V ca. 70 Wh/l to 400 Wh/l or higher)

Energy per mass (S/M ca. 40 Wh/Kg to 150 Wh/Kg or higher)

Cycle life (20,000 cycles guaranteed—typically over 100,000 cycles)

Thermal stability (TUpper>60 C and typically ca. 70 C or higher, and TLower less than −10 C and typically ca. −40 C or lower)

High charge (RC and RE≥70% of initial charge voltage)

High energy retention (minimum 180 days after charging)

High charge and discharge capability (IC and ID≥1.2 C where C is equal to the amount of current required to discharge to its termination voltage within a 1-hour period)

Excellent safety factor—based on third-party safety testing for fire and explosion

Superb recyclability

Fast Charge/Discharge Capabilities

A graphene battery (also referred to as a “supercapacitor”) is more efficient and more environmentally friendly than other types of batteries. Multiple capacitors can be used in series or parallel without adverse reaction. Voltage management or voltage monitoring circuitry is not necessary to enable charging or fast charging of the device when used in parallel with electrical configurations. This reduces cost and enables better utilization of the device in demanding environments.

Capacitance (C) of the supercapacitor is achieved through electronic double layer capacitance and electrochemical capacitance. This effect is maximized with the addition of one or more oxides of magnesium or magnesium dioxide.

Optimization of the microstructure enables reductions and reaction of oxides to incur per unit mass or volume of depleted material. This creates nanostructures and allows consistent and relatively uninhibited access to electrolyte thereby maximizing the number of oxides per unit mass.

Construction

FIG. 1 illustrates an example composition of a supercapacitor 100 according to some embodiments of the disclosure. In some embodiments, the supercapacitor 100 includes multiple layers that are affixed together (e.g., stacked on top of each other using an adhesive material). In this example, the supercapacitor 100 includes external layers 102 and 104 that may be made with plastic. The supercapacitor 100 may also include one or more layers of graphene battery sheets disposed between the external layers 102 and 104. In this example, the supercapacitor 100 includes two layers of graphene battery sheets 106 and 108. However, other numbers (e.g., 4, 8, 10, etc.) of layers of graphene battery sheets can be incorporated into the supercapacitor 100 in some embodiments. A separator layer 110 may be disposed between two adjacent layers of graphene battery sheets. In this example, the separator layer 110 separates the layer of graphene battery sheet 106 and the layer of graphene battery sheet 108. In some embodiments, the separator layer 100 includes electrolyte.

In some embodiments, a supercapacitor may include one or more electrode plates (also referred to as “graphene layers”), one or more isolation films (also referred to as “separator layers”), a pole, and a housing. Each of the electrode plates may include a current collector and a coating. The coating may include a combination of an active material, a conductive agent, and an adhesive material in the mass ratio of (70-95):(2-20):(3-10). In some embodiments, the active material may include a carbon material, a conductive polymer, and a graphite-type carbon nitride in the mass ratio of (60-90):(5-30):(5-10). The carbon material may include nitrogen-doped graphene that has been functionalized with poly 3-hexylthiophene. The surface of the graphene may be deposited with oxides of manganese dioxide nanoparticles. Polyaniline is used as the conductive polymer.

Anode foil (which can be made with aluminum and/or other materials) and cathode foil (which can also be made with aluminum and/or other materials) may be layered together. A separator may be placed between them. A coating layer that may include a homogenous mixture of an active material, a conductive agent, and an adhesive (in the mass ratio of (70-95):(2-20):(3-10)) may be formed on top of the layer of anode foil followed by the layer of cathode foil.

The ends of lead wires are connected to the anode foil then the cathode foil. Ends are then led out from the capacitor element. An outer housing accommodates the capacitor element and may be filled with an electrolyte solution. The outer housing is formed into a flat pack with a sealing body. The sealing body includes through holes for lead wires. After passing lead wires through, the outer housing is compressed to seal the opening and prevent access to internal structures.

The active material used for the coating (and/or the coating layer) may include a mixture of carbon material conductive polymer and graphite-type carbon nitrate in the mass ratio of 60-90:50-30:5-10. The carbon material may include nitrogen doped graphene that has been functionalized with 3-hexylthiophene (polymer). The surface of the graphene may be deposited with nanoparticles of manganese dioxide.

The mass ratio of polymer to graphene is 1:(10-40). The particulate size of the magnesium dioxide nanoparticles is between 10 nm and 1 μm or 50 nm and 500 nm. The mass ratio of the total mass of the oxides of manganese dioxide nanoparticles to graphene may be 1:(10-30). The conductive polymer has an average molecular weight of 1,000 to 1,000,000. In some embodiments, the supercapacitor may include between 20 and 100 layers of graphene. Each graphene layer has a layer thickness of 1.0 nm to 4.0 nm.

FIG. 2 illustrates an example supercapacitor 200 according to various embodiments of the disclosure. The supercapacitor 200 may include a positive electrode plate 202 and a negative electrode plate 204. While only a pair of electrode plates 202 and 204 is shown in FIG. 2 , additional pairs of positive and negative electrode plates can be included in the supercapacitor 200 according to some embodiments. In some embodiments, each the electrode plates 202 and 204 may include an aluminum foil 208. For example, the positive electrode plate 202 may include an anode foil and the negative electrode plate 204 may include a cathode foil. In some embodiments, the electrode plates 202 and 204 (and other adjacent electrode plates) may be separated by separator layers 206. The different layers (e.g., the electrode plates 202 and 204, and the separator layers 206) may be enclosed within a housing (not shown) that is filled with electrolyte 210.

The porous structure of the graphene facilitates extremely fast transmission of ions. This improves the electrochemical performance of the supercapacitor. The graphite-type carbon nitride has a porous structure with a pore diameter of 2 nm to 200 nm and a mesoporous structure with a pore diameter ranging from 10 nm to 20 nm. The mesoporous structure provides a large surface area which proves useful for maximizing the amount of electronic double layer area. FIG. 3 illustrates a cross section of at least a portion of a supercapacitor 300 according to various embodiments of the disclosure. The supercapacitor 300 may include a positive electrode plate 302 that may correspond to the positive electrode plate 202, a negative electrode plate 304 that may correspond to the negative electrode plate 204, and a separator layer 306 that may correspond to the separator layer 206. The supercapacitor 300 may also include electrolyte ions within a housing (not shown) for the electrode plates 302 and 304 and the separator layer 306, that is filled with electrolyte ions 310 that may correspond to the electrolyte 210. As shown, the positively charged and negatively charged electrolyte ions 310 can travel through the separator layer 306 freely to reach the corresponding electrode plates 302 and 304. In some embodiments, the supercapacitor 300 may also include current collector layers 312 and 314 for collecting current from the electrode plates 302 and 304, and feeding the current to an external device.

FIGS. 4A and 4B illustrate different supercapacitor configurations according to various embodiments of the disclosure. FIG. 5 illustrates an example coating that can be used on the electrode plates.

Components

In order to prepare the graphene oxide functionalized with 3-hexylthiophene, thionyl chloride (SOC12) is added to an unsaturated dimethylformamide (DMF) solution at a mass ratio of SOC12 to graphene oxide of 1000:1 and 300:1. The mixture of SOC12, graphene oxide, and DMF is heated to 70° C.-90° C. in a nitrogen production atmosphere. It is reacted for 10 to 30 hours.

Excess DMF is removed by steaming under reduced pressure. The mixture is vacuum dried at 40° C.-70° C. This produces acyl chlorinated graphene oxide (ACGO) which is dispersed in DMF at a mass ratio of ACGO to DMF of 1:3,000 to 1:10,000.

The mixture is then uniformly stirred in an inert atmosphere of nitrogen gas. 0.01 w % to 0.03 w % of 3-thiophenecarboxylic acid is added and mixed for 20-60 minutes. 1.5% to 4.6 w % of triethylamine is added. The mixture is then heated to 110° C.-130° C. and stirred for another 10-30 hours.

Excess 3-thiophenecarboxylic acid is centrifugally removed and the remaining supernatant acetylated product is transferred to a reaction vessel. Anhydrous chloroform is added at a level of 25V % to 60V % and the mixture is ultrasonically reacted for 40-80 minutes. A chloroform solution of 3-hexylthiophene, with a concentration of 15 mg/mL to 30 mg/mL 3-hexylthiophene is added to the mixture at 6.5V % to 17.5V %. The resulting mixture is stirred for 10 to 30 hours before anhydrous ferric chloride is added at a level of 0.3 w % to 1.1 w %. It is then reacted at room temperature for 10-24 hours. Once complete, the solution is poured into excess methanol and purified using a Soxhlet extraction method and vacuum dried for 3-10 hours.

To prepare the nitrogen-doped graphene functionalized with polymer, urea and distilled water are added to the graphene oxide that has been previously functionalized with 3-hexylthiophene. The mixture is combined using an ultrasonic mixer. It is then dried at 30° C.-50° C. and transferred to a PTFE-lined hydrothermal reactor where it is reacted for 1-5 hours at 130° C. The resulting solid product is cooled to room temperature and washed.

The nitrogen-doped graphene functionalized with 3-hexylthiophene is mixed with MnC124H2O and isopropanol and heated to 60° C.-85° C. A suitable amount of KMnO4 is added to the solution and reacted at 60° C.-85° C. for 1-3 hours. The resulting black precipitate is then centrifuged, washed, dried, and ground. 

1. A power management system, comprising: a first interface communicatively coupled to an electricity grid associated with a premises; a second interface communicatively coupled to a graphene battery; one or more hardware processors; and a non-transitory memory storing instructions that when executed by the one or more hardware processors cause the one or more hardware processors to perform operations comprising: providing power to appliances within the premises under a first operation mode, wherein the first operation mode specifies the electricity grid as a sole power source for the appliances; detecting an abnormal event associated with the electricity grid associated with the premises; and in response to the detecting, configuring the power management system to provide power to the appliances under a second operation mode, wherein the second operation mode specifies the graphene battery as the sole power source or a partial power source for the appliances.
 2. A supercapacitor comprising: a housing comprising electrolyte; one or more layers of graphene battery sheets within the housing; and one or more of separator layers disposed between each adjacent pair of the one or more layers of graphene battery sheets within the housing.
 3. The system of claim 1, further comprising one or more solar panels electrically connected to and configured to supply energy to the graphene battery.
 4. The system of claim 1, wherein the one or more solar panels are located on the premises.
 5. The system of claim 1, wherein the graphene battery comprises a first insulating layer, a second insulating layer, and a graphene electrode disposed between the first insulating layer and the second insulating layer.
 6. The system of claim 5, wherein the graphene battery comprises two graphene electrodes disposed between the first insulating layer and the second insulating layer and a separator between the graphene electrodes.
 7. The system of claim 6, wherein the separator comprises an electrolyte.
 8. The system of claim 5, wherein the graphene electrode comprises a current collector and an active material coating disposed on the current collector, wherein the active material coating comprises a carbon material, a conductive polymer, and a graphite nitride.
 9. The system of claim 8, wherein a mass ratio between the carbon material, the conductive polymer, and the graphite nitride is 70-95:2-20:3-10.
 10. The system of claim 9, wherein the carbon material comprises nitrogen-doped graphene.
 11. The system of claim 10, wherein the nitrogen-doped graphene is functionalized with poly 3-hexylthiophene.
 12. The system of claim 9, wherein the carbon material comprises graphene comprising manganese dioxide nanoparticles on surfaces thereof.
 13. The system of claim 9, wherein the conductive polymer has an average molecular weight of 1,000 to 1,000,000; and wherein the graphite nitride comprises nanopores having a pore diameter of 2 to 200 nm.
 14. The supercapacitor of claim 2, wherein the graphene battery sheets each comprise a current collector and an active material coating disposed on the current collector, wherein the active material coating comprises a carbon material, a conductive polymer, and a graphite nitride.
 15. The supercapacitor of claim 14, wherein a mass ratio between the carbon material, the conductive polymer, and the graphite nitride is 70-95:2-20:3-10.
 16. The supercapacitor of claim 15, wherein the carbon material comprises nitrogen-doped graphene functionalized with poly 3-hexylthiophene.
 17. The supercapacitor of claim 15, wherein the carbon material comprises graphene comprising manganese dioxide nanoparticles on surfaces thereof.
 18. The supercapacitor of claim 17, wherein the manganese dioxide nanoparticles have a particulate size of 10 nm to 1 micron.
 19. The supercapacitor of claim 17, wherein a mass ratio of the conductive polymer to graphene is 1:10 to 1:40 and a mass ratio of manganese dioxide particles to graphene is 1:10 to 1:30.
 20. The supercapacitor of claim 2, comprising 20 to 100 layers of graphene, each layer having a thickness of 1 to 4 nm. 